Poltergeist

The mother of a haunted family saves her daughter by diving into the underworld, and the experience turns much of her hair gray. Aside from that, not much.

--Zietgiest

Poltergeist: The Legacy

TV Series: Season 01; Episode #02: "Pilot - Part 2" (21-Apr-1996)

A demonic child is born which can assume any form and uses this ability to prey on the Legacy's weaknesses and desires. First, he appears to the priest as his fiancee Anna and seduces him. Next, he appears as the recently-deceased Julia. Third, he takes on the form of the the little girl.